In one of the past forums, I reported intermittent cooling water flow. Since then I have isolated the problem. It is due to rust inside the engine cooling passages (raw water cooled combined with never-replaced zincs). I created a flush kit and back flushed the engine several times, getting lots of small rust flakes and particles. Things are working much better now but I know the problem is not gone.
Does anyone have any experience with descaling acids? A book I have by Nigel Calder suggests a product called Saf Acid. In lieu of that, he suggests Oxalic or Phosphoric Acid. I am having a hard time finding a source for any of these acids.
A warning: do not use vinegar. A friend suggested using vinegar to dissolve the rust. I tried it on the thermostat housing. It actually dissolved the cast iron as well as the rust. The threads pulled right out with no effort at all.
Comments?
